SUEZ, Egypt — Egyptian protesters threw Molotov cocktails at a government building in the port city of Suez on Wednesday, setting parts of the building on fire, witnesses said, on the second day of nationwide anti-government protests.

Protesters also lobbed firebombs at the headquarters of the ruling National Democratic Party, amid heavy clashes between protesters and police, who tried to disperse the crowd with tear gas and rubber bullets, witnesses said.

At least 70 people — 55 protesters and 15 police officers — were injured in the clashes, medics said.

In demonstrations across Egypt Tuesday, three protesters and a policeman were killed.

The interior ministry has banned all further demonstrations and promised a crackdown. Security officials said 700 people had been arrested over the two days.